Non-pharmacological treatment – Probiotics -particularly Lactobacillus, which may be found in fermented milk products such as yogurt with active cultures. This type of bacteria helps to maintain a vaginal pH that is not conducive to bacterial growth and demonstrates antimicrobial properties (Kumar, et al., 2011).

Can anyone tell me what is wrong with this citation? I was told that this is NOT the correct way to cite a reference according to SIXTH edition APA format.

Question

Non-pharmacological treatment – Probiotics -particularly Lactobacillus, which may be found in fermented milk products such as yogurt with active cultures. This type of bacteria helps to maintain a vaginal pH that is not conducive to bacterial growth and demonstrates antimicrobial properties (Kumar, et al., 2011). 

Can anyone tell me what is wrong with this citation?  I was told that this is NOT the correct way to cite a reference according to SIXTH edition APA format.